MULTI-MECHANICAL IN SITU TESTING FOR AUTOMOTIVE INDUSTRY DLC/INTERLAYER/M2-STEEL COATINGS

摘要

Wear resistance enhanced mechanical components with lower friction can help to answer to automotive industry challenges such as high performance, improved reliability and environmental friendly production. Diamond Like Carbon (DLC) deposited on mechanical components efficiently decrease the friction coefficient and insure wear protection [1]. DLC hard coatings, produced by Plasma Enhanced Chemical Vapor Deposition (PECVD), exhibit high compressive residual stress [2]. In order to improve coating adhesion, an appropriate interlayer is pre-deposited on mechanical components. However, in severe conditions, local coating delamination initiated by blistering is still occasionally detected [3]. To understand wear induced damage in DLC coated material and to optimize the coating/interlayer/substrate system design, very local and reliable mechanical data are required. The present work is dedicated to the investigation of mechanical properties of industrial DLC coatings. Several advanced experimental techniques were used to characterize DLC /interlayer/M2Steel samples. Residual stress was investigated by the combination of FIB-machined micro-beams flexion analysis and finite elements modeling (cf.Fig.1). In situ nano-indentation and FIB-milled micro-pillar compression (cf. Fig.2) were also performed to determine some mechanical date that were then implemented in numerical model to simulate DLC damage. A specific attention was taken on the properties of both normal/transverse sides of the coatings.